Rabu, 29 Desember 2010

The Maserati GranTurismo S, the sportiest version of Maserati’s coupé, was developed for those looking for a distinctive performance car. The new and powerful 4.7 litre V8 engine is capable of generating 323 kw (440bhp), bestowing the GranTurismo S with a distinctive personality, aggression and power; all the necessary traits to deliver a refined drive in complete safety.

The transaxle set up employed in the design of the engine and gearbox is a stunning example of Maserati technology. The suspension makes the most of this system thanks to new fixed-rate dampers that now offer 10% more damping. The compression and extension ratios have also been tweaked and the rear torsion bar stiffened. The brakes, developed in collaboration with Brembo, always give a prompt response thanks to their dual cast iron and aluminium discs.

The sporty feel of the GranTurismo S is accentuated by Pininfarina’s modern lines. The detailing on the car renders it unmistakable. Features include red prongs on the Trident, the Saetta logo mirror and the standard colour of the brake callipers, features that distinguish competition Maseratis. Style, elegance and safety, combined with extraordinary performance, makes driving the Maserati GranTurismo S a thrilling experience that can be enjoyed every day.

GranTurismo S is powered by a 4.7-liter V8 in place of the unit regular GT's 4.2-liter. Output of 433 horsepower at 7000 rpm with a torque rating of 360 lb-ft at 4750 rpm, repair 28, and 21 respectively. In S, an MC-Shift replace sophisticated dual-clutch six-speed ZF automatic transmission. The changes at the highest speed for the S 183 mph, up from 177 mph, and reached 62 mph from stop nearly three-tenths of seconds faster, at 4.93. Because the transaxle configuration, weight distribution over the rear S-bias, at 53 percent, compared with 51 percent of the ordinary car was rear bias.

New high power Brembo brakes increase stopping distance and offers a high resistance to fade. Maserati claims the car can stop from 62 mph in less than 115 meters. This system has a front brake discs made with dual-cast technology, so that pairs up iron and aluminum for a better weight, heat transfer properties, and extorted by a mono-block calipers aluminum 6-piston.

Compared with the standard GranTurismo, S rides on unique 20-inch wheels, up from 19-inch wheels. Other exterior visual differences between the two sides of skirts and unique integrated spoiler. The dimensions of the GranTurismo and S are nearly identical, although S is 2.7 inches wider.

In addition to the above changes, the S features of a conventional suspension set-up, aggressively tuned to reduce roll by 10 percent compared with the GranTurismo pedestrians. Electronically-adjustable Skyhook suspension was found in a weaker car is an option. Interior Poltrona Frau leather and Alcantara for luxury increased, and include more aggressive seat supported.

Engine

The Maserati GranTurismo S is powered by an eight cylinder, 4,691 cc V90° engine that develops 440 bhp at 7,000 rpm and produces a maximum torque of 490 Nm at 4,750 rpm. The timing is actioned by two overhead camshafts per bank and four valves per cylinder controlled by hydraulic tappets. The overhead camshafts on the aspirated side are controlled by a low pressure, continual phase variator with an actuation time of less than 0.15 seconds.

The 4.7 litre V8’s maximum power is achieved at 7,500 rpm but can reach 7,600 rpm in dynamic conditions with on-the-limit gear changes. The power unit is one of Maserati’s new breed of wet sump engines.

Exhaust

The engines deep throaty sound can be fully appreciated thanks to the sports exhaust. However, the engine noise never interferes with the on-board comfort you would expect from a true grand tourer.

The set up features two steel exhaust pipes, one for each cylinder bank, that are compensated by a central silencer. Two pneumatic valves are set close to the rear silencers and are controlled electronically by the engine’s central computer. They can be managed by the driver by pushing the ‘Sport’ button on the central console. The new exhaust system is instantly recognisable thanks to its distinctive tailpipes where the two outlets come together in an eye-catching single chrome oval.

Gearbox

From a technical point of view, the electro-actuated gearbox fitted to the Maserati GranTurismo S has a six-speed (plus reverse), twin disc clutch, with a triple cone synchroniser on the first and second gears and a double cone on the other gears.

The twin disc clutch derives from the world of competition and is particularly suitable for sports cars: the reduced size of the clutch group (215 mm), and the small diameter of the flywheel (240 mm), keeps the unit’s overall weight down. This notably reduces the engine’s inertia compared to a single disc set up. The system also allows top end revs to be reached more easily, resulting in a quicker response from the gears, faster shifts and improved gear dynamics.

The electro-actuated transmission can be used in two ways: manual and automatic. Manual mode is for those who prefer a sportier, more involving driving experience with gear changes only made if the driver requests them in order to fully unlock the car’s performance. Automatic mode is designed for when the driver wants a relaxing drive: the system decides not only when to change gear but at what revs.

MC-Shift

The MC-Shift gearbox is the biggest innovation on the electro-actuated system fitted to the Maserati GranTurismo S. MC-Shift is a management and components software that allows super fast gear change times.

On the Maserati GranTurismo S, the gear changes partially overlap and engaging and disengaging the gear happens before the clutch fully opens and shuts. This means that gear changes, taken as the time from when the foot comes off the accelerator, drops to 100ms, while the gear shift itself takes 40ms.

The fast MC-Shift is only available when changing up and in Manual Sport mode when the gearbox computer recognises that the parameters relative to the temperature of the engine and gearbox have been reached. The fast changes can be made above 5,500 revs and with the accelerator pedal at 80% opening. Once these parameters have been reached, the system enables fast changes and advises the driver of this via the MC-S light on the instrument panel.

Transaxle set up

The Maserati GranTurismo S is equipped with a transaxle system, part of Maserati’s proud technical tradition and that is found on many high performance sports cars. The transaxle set-up further improves the weight distribution of the GranTurismo by shifting the gearbox to the rear in a single block with the differential. The mid-mounted engine is firmly connected to the electro-actuated gearbox, set in the rear, via a rigid tube that houses the drive shaft. These solutions give the Maserati GranTurismo S a front-rear weight distribution of 47%-53%, unique in its segment.

Suspension

The Maserati GranTurismo S comes with fixed-setting suspension that is now fitted with new springs and dampers to offer 10% more damping. The compression and extension ratios have also been tweaked and adapted to the car’s specific characteristics and the rear torsion bar has been reinforced.

The Skyhook system

As an alternative to fixed rate dampers, the electronically controlled Skyhook suspension is available as an option. This system employs dampers with an aluminium body that continually adjust the damping.

The Skyhook system acts by using acceleration sensors that detect movement on all four wheels and the body. A control unit processes the data it receives from the sensors, analyses the driving style and road surface and instantly adjusts the dampers accordingly via their proportional valves. However, as the Skyhook and transmission data from the sensors is fed to the same point, Maserati engineers have integrated the two systems. As such, the GranTurismo S is able to fine tune the suspension settings so that the driver feels even less movement through the chassis during gear changes.

Opting for the ‘Sport’ setting results in a stiffer ride, less roll, more contained load transfer, greater agility and stability as well as allowing startling performance figures. The dedicated on board computer reduces gear shifts by 40% and Skyhook switches from controlling the ride to focusing on the set up (body control), making the GranTurismo easier to handle and giving it more grip. Together, the two systems combine to offer more precise and involving gear changes.